From f5bd280b51fcbffc12ece0ae1d26511f73f7936a Mon Sep 17 00:00:00 2001
From: blobfish <blobfish@gmx.com>
Date: Fri, 2 Jun 2017 15:43:54 -0400
Subject: [PATCH] osg: KdTree: count degenerates to keep original primitive
 index in sync

---
 include/osg/KdTree | 10 +++++-----
 src/osg/KdTree.cpp |  6 +++++-
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/osg/KdTree b/include/osg/KdTree
index 8ebe80bd0..33f90ac98 100644
--- a/include/osg/KdTree
+++ b/include/osg/KdTree
@@ -69,7 +69,7 @@ class OSG_EXPORT KdTree : public osg::Shape
         inline unsigned int addPoint(unsigned int p0)
         {
             unsigned int i = _vertexIndices.size();
-            _vertexIndices.push_back(_primitiveIndices.size());
+            _vertexIndices.push_back(_primitiveIndices.size() + _degenerateCount);
             _vertexIndices.push_back(1);
             _vertexIndices.push_back(p0);
             _primitiveIndices.push_back(i);
@@ -78,7 +78,7 @@ class OSG_EXPORT KdTree : public osg::Shape
         inline unsigned int addLine(unsigned int p0, unsigned int p1)
         {
             unsigned int i = _vertexIndices.size();
-            _vertexIndices.push_back(_primitiveIndices.size());
+            _vertexIndices.push_back(_primitiveIndices.size() + _degenerateCount);
             _vertexIndices.push_back(2);
             _vertexIndices.push_back(p0);
             _vertexIndices.push_back(p1);
@@ -89,7 +89,7 @@ class OSG_EXPORT KdTree : public osg::Shape
         inline unsigned int addTriangle(unsigned int p0, unsigned int p1, unsigned int p2)
         {
             unsigned int i = _vertexIndices.size();
-            _vertexIndices.push_back(_primitiveIndices.size());
+            _vertexIndices.push_back(_primitiveIndices.size() + _degenerateCount);
             _vertexIndices.push_back(3);
             _vertexIndices.push_back(p0);
             _vertexIndices.push_back(p1);
@@ -101,7 +101,7 @@ class OSG_EXPORT KdTree : public osg::Shape
         inline unsigned int addQuad(unsigned int p0, unsigned int p1, unsigned int p2, unsigned int p3)
         {
             unsigned int i = _vertexIndices.size();
-            _vertexIndices.push_back(_primitiveIndices.size());
+            _vertexIndices.push_back(_primitiveIndices.size() + _degenerateCount);
             _vertexIndices.push_back(4);
             _vertexIndices.push_back(p0);
             _vertexIndices.push_back(p1);
@@ -179,7 +179,7 @@ class OSG_EXPORT KdTree : public osg::Shape
             }
         }
 
-
+        unsigned int _degenerateCount;
 
     protected:
 
diff --git a/src/osg/KdTree.cpp b/src/osg/KdTree.cpp
index 9d03020e8..709c12f99 100644
--- a/src/osg/KdTree.cpp
+++ b/src/osg/KdTree.cpp
@@ -86,6 +86,7 @@ struct PrimitiveIndicesCollector
         if (v0==v1)
         {
             //OSG_NOTICE<<"Disgarding degenerate triangle"<<std::endl;
+            _buildKdTree->_kdTree._degenerateCount++;
             return;
         }
 
@@ -111,6 +112,7 @@ struct PrimitiveIndicesCollector
         if (v0==v1 || v1==v2 || v2==v0)
         {
             //OSG_NOTICE<<"Disgarding degenerate triangle"<<std::endl;
+            _buildKdTree->_kdTree._degenerateCount++;
             return;
         }
 
@@ -138,6 +140,7 @@ struct PrimitiveIndicesCollector
         if (v0==v1 || v1==v2 || v2==v0 || v3==v0 || v3==v1 || v3==v2)
         {
             //OSG_NOTICE<<"Disgarding degenerate quad"<<std::endl;
+            _buildKdTree->_kdTree._degenerateCount++;
             return;
         }
 
@@ -481,12 +484,13 @@ KdTree::BuildOptions::BuildOptions():
 //
 // KdTree
 
-KdTree::KdTree()
+KdTree::KdTree() : _degenerateCount(0)
 {
 }
 
 KdTree::KdTree(const KdTree& rhs, const osg::CopyOp& copyop):
     Shape(rhs, copyop),
+    _degenerateCount(rhs._degenerateCount),
     _vertices(rhs._vertices),
     _kdNodes(rhs._kdNodes)
 {